Bug#534274: [mdadm] mdadm fails to assemble raid array on boot with kernel > 2.6.26

[Lior Chen]

Package: mdadm
Version: 2.6.9-3
Severity: grave

--- Please enter the report below this line. ---
Hi,

With kernels newer than 2.6.26-2 (I have tried both 2.6.29-2 and 2.6.30-1) 
mdadm fails to assemble raid array on boot:

Assembling all MD arrays... md: md0 stopped
mdadm: no devices found for /dev/md0
Failure: failed to assemble all arrays.

After the system gives up waiting for the root device, I get an initramfs 
shell, and then I when I try to build the raid-array myself, using either:

mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sda2 /dev/sdb2
or 
mdadm -A /dev/md0 /dev/sda2 /dev/sdb2

it fails saying that /dev/sda2 and /dev/sdb2 are busy (mdadm: Cannot open 
/dev/sda2: Device or resource busy).

Please tell me if there is any more information I can provide that could be of 
help. 

Thank you,
          Lior


-----------

Some additional information:

in the initramfs shell:
ls -l /dev/mapper :
control
isw_cjhfigcfig_LCRAID
isw_cjhfigcfig_LCRAID1
isw_cjhfigcfig_LCRAID2

=== raid-0 (striping) structure ===

/dev/sda2 - first raid device
/dev/sdb2- second raid device


=== cat /proc/mdstat ===

Personalities : [raid0]
md0 : active raid0 sda2[0] sdb2[1]
      488199040 blocks 64k chunks

unused devices: <none>

=== /etc/mdadm/mdadm.conf ===

# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
DEVICE /dev/sda2 /dev/sdb2

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY /dev/md0 level=raid0 num-devices=2 
UUID=b4c9005d:7337b4ba:77fef61e:a74ffb27

# This file was auto-generated on Sun, 21 Jun 2009 00:19:47 +0300
# by mkconf $Id$


=== /proc/partitions ===
major minor  #blocks  name

   8     0  244198584 sda
   8     1      96358 sda1
   8     2  244099642 sda2
   8    16  244198584 sdb
   8    18  244099642 sdb2
   9     0  488199040 md0
 253     0    4194304 dm-0
 253     1  484003840 dm-1


--- System information. ---
Architecture: amd64
Kernel:       Linux 2.6.26-2-amd64

Debian Release: squeeze/sid
  500 unstable        www.debian-multimedia.org 
  500 unstable        mirror.hamakor.org.il 

--- Package information. ---
Depends        (Version) | Installed
========================-+-============
libc6         (>= 2.3.3) | 2.9-18
udev                     | 0.141-1
 OR makedev              | 2.3.1-88
debconf      (>= 1.4.72) | 1.5.26
lsb-base      (>= 3.1-6) | 3.2-22


Recommends                (Version) | Installed
===================================-+-===========
default-mta                         | 
 OR mail-transport-agent            | 
module-init-tools                   | 3.9-2


Package's Suggests field is empty.


--- Output from package bug script ---